cultural milestone tonight in this country, someone who changed the way we go to the movies has died. Roger ebert and hisleague gene siskel turned our kitche kitchen-table arguments about good movies and bad movies into a national event. Abc's david muir is here now to show us the path of the pioneer. What an incredible path it was. His thumb could determine the fate of a movie here in america. We knew he loved to talk and despite his biggest hurdles in the event, he was still talking. Reporter: Siskel and ebert wasn't just a show. Their words could drive americans to the movies. They were the critics who famously feuded but it was when they saw eye to eye delivering their trademark two thumbs up. That could help send a movery to number one. There were studies through the years, showing those two thumbs could deliver huge dividends for a movie. Roger ebert was the first film critic to win a pulitzer prize for his work millions of americans recognized him as the reviewer who loved to talk the sweaters, the trademark glasses. He and his longtime reviewing partner gene siskel would spar many said like a longtime married couple. What about the characters! Reporr: Gene siskel died in 1999 of a brain tumor. And years later, roger ebert would face his greatest challenge too, cancer. Losing portions of his jaw and his ability to speak, eat and drink after cancer surgeries. Turning to a computer generated voice to do the speaking for him. These are my words but this is not my voice. This is alex, the best computer voice I've been able to find. Reporter: He would speak of the gift of talking, a gift he took for granted. For most of my life I never gave a thought to my ability to speak. It was like breathing. I was living in a fool's paradise. After surgeries for cancer took away my ability to speak, eat or drink, I was forced to enter this virtual world in which a computer does some of my living for me. Reporter: On oprah ebert would describe using a computer generated voice that in his dreams he could still speak. That's just like I was in life, you could never shut me up. Reporter: Ebert taking note it was 46 years ago, april 1967 he became a film critic, telling his followers, I'm not going away. Hoping to still write reviews while he battled cancer. Ending his letter, he said, on this day of reflection, I say again, thank you for going on this journey with me. I'll see you at the movie. Eddy murphy once joked if they called it a horrible picture, they could kill a movie. And oprah tweeting today,s siskel and ebert back together today, end of an era.

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